package com.example.nextstream.config;

import com.example.nextstream.annotations.CurrentUser;
import com.example.nextstream.models.User;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.MethodParameter;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.method.support.ModelAndViewContainer;
import org.springframework.web.multipart.support.MissingServletRequestPartException;

import java.io.Console;

/**
 *  增加方法注入，将含有 @CurrentUser 注解的方法参数注入当前登录用户
 */
@Component
public class CurrentUserMethodArgumentResolver implements HandlerMethodArgumentResolver {
    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.getParameterType().isAssignableFrom(User.class)
                && parameter.hasParameterAnnotation(CurrentUser.class);
    }

    @Override
    public Object resolveArgument(MethodParameter parameter,
                                  ModelAndViewContainer mavContainer,
                                  NativeWebRequest webRequest,
                                  WebDataBinderFactory binderFactory) throws Exception {

        User user = (User)webRequest.getAttribute("currentUser",RequestAttributes.SCOPE_REQUEST);
        if (user != null) {
            return user;
        }
        throw new MissingServletRequestPartException("currentUser");
    }
}
